KUALA LUMPUR, Sept 13 — The addition of Takeda’s dengue vaccine into Malaysia national immunisation programme (NIP) can reduce symptomatic dengue cases, hospitalisation, and save the country up to US$1 billion (RM4.3 billion) over the next three decades, according to a dengue modelling analysis.
A routine dengue vaccination programme for school children starting at age 7 years, including catch-up cohorts, can prevent 34 to 42 per cent of symptomatic cases and 38 to 47 per cent of hospitalised cases over a period of 20 years, based on a model calibrated to local dengue incidence.
Dr Amirah Azzeri, the study’s lead author and senior lecturer at Universiti Sains Islam Malaysia (USIM), said the study examined various combinations of routine and catch-up vaccination strategies from age seven to 13 to determine an optimal dengue vaccination strategy for Malaysia.
“The study finds that the most optimal strategy is to introduce one routine and four catch-up cohort vaccinations starting at age seven,” Dr Amirah said during a presentation of the study at the 7th Asia Dengue Summit 2024 here last June 6.
Dengue presents a significant burden in Malaysia, with reported cases surging by 86.3 per cent from 66,102 in 2022 to 123,133 in 2023. Dengue deaths also increased by 78.6 per cent, from 56 in 2022 to 100 in 2023.
Dr Amirah said that under an illustrative vaccine price of US$25 (RM108.80) per dose, all vaccination strategies tested in the study demonstrated significant cost savings over a period of 10 to 30 years.
Assuming a routine cohort coverage of 85.9 per cent and catch-up cohort coverage of 60 per cent, a national dengue vaccine campaign could save up to US$1.06 billion (RM4.6 billion) over 30 years at the societal level and US$307 million (RM1.3 billion) at the payer level.
The study’s cost parameters include direct medical expenses like doctor visits, hospitalisations, medications, tests; non-medical costs including transportation, meals, accommodation related to treatment; and indirect costs such as productivity losses.
Health Minister Dzulkefly Ahmad recently told reporters that including dengue vaccination in the NIP will take time, primarily due to the high cost of the vaccine. Malaysia’s NIP, first introduced in the 1950s, currently offers protection against 13 major childhood diseases.
The Drug Control Authority (DCA) conditionally approved the use of Takeda’s dengue vaccine in February to prevent dengue fever in individuals aged four years and older.
The live-attenuated dengue tetravalent vaccine by the Japanese pharmaceutical company has shown long-term safety and efficacy for up to 4.5 years against symptomatic and hospitalised dengue cases, based on the TIDES study involving over 20,000 children and adolescents.
The World Health Organization (WHO) recommends the programmatic use of Takeda’s dengue vaccine in children aged six to 16 years in settings with high dengue burden and transmission intensity for large-scale vaccination programmes. The vaccine should be administered in a two-dose schedule with a three-month interval between doses.
Lessons From Brazil’s Dengue Vaccination Campaign
Brazil became the first country to integrate the two-dose dengue vaccine into its public health care system, following a surge in dengue cases that alarmed health authorities.
Rapid urbanisation, warmer temperatures, and heavier rainfalls create ideal conditions for the Aedes aegypti mosquito that spreads the dengue virus.
In 2023, the Americas recorded the highest number of dengue cases ever, with 4,617,101 cases and 2,423 deaths, according to the Pan American Health Organization (PAHO). Brazil alone accounted for over three million cases.
The latest PAHO figures for 2024 show that dengue cases in the Americas have far outpaced last year’s record, reaching 8,991,508 cases and 4,157 deaths, with Brazil recording more than 7.5 million cases.
With Brazil facing its worst dengue outbreak, new interventions and advancements in vector control and dengue vaccines are crucial for managing the expanding threat, said infectious disease physician and adjunct associate professor of epidemiology at the Yale School of Public Health, Prof Dr Julio Croda.
The vaccine received registration approval from Brazil’s national drug regulator Anvisa in March 2023, allowing it to be marketed in Brazil under approved conditions.
In December 2023, Brazil’s Ministry of Health announced the vaccine’s incorporation into the public health care network.
The doses began distribution in January this year to 521 municipalities selected by the health ministry to initiate vaccination within the Brazilian public health system. These municipalities represent only 9 percent of the 5,570 municipalities in Brazil.
The selected cities will vaccinate children and adolescents aged 10 to 14, a demographic with the second-highest number of dengue-related hospitalisations, second only to the elderly.
The municipality of Dourados, located in the state of Mato Grosso do Sul, was the first city in Brazil to launch a mass dengue vaccination campaign, targeting to vaccinate 120,000 individuals aged between four and 60.
Dourados experienced a high incidence of dengue in 2023, with 1,388 cases per 100,000 inhabitants or a total of 3,378 cases in a population of 243,368.
“Children aged under 10 to 14 still have one of the lowest vaccination coverage in general,” Dr Croda said, in summarising the lessons learned from Brazil’s dengue vaccination campaign to date.
He attributed the low uptake of the dengue vaccine among this group to limited awareness of dengue mortality and morbidity, and highlighted the necessity of an effective communication campaign to complement vaccination efforts.
